As long as there have been automatic baggers, the goal of designers of them has been to collect and bag at least a predetermined weight of fruit or other discrete articles to be bagged, but exceeding the predetermined weight, by the smallest amount possible. Small savings per bag translate into large yearly savings. For example in equipment for forming three pound bags of apples, with fruit of a size between 4 to 6 oz., a savings of as small an amount as 1.5 oz. per bag can result in yearly savings in the tens of thousands of dollars per bagger. However the bagging operation must not be slowed considerably in order to effect these savings, and the equipment for bagging must be cost effective considering these savings.
According to the present invention, a method and apparatus are provided which are able to minimize the amount of overage of fruit or other discrete articles during collecting, bagging, and like operations, in an inexpensive, cost effective manner. For example the primary equipment utilized to perform the automatic bagging function according to the invention need only be about six feet long, and costs only about $15,000 in 1993 U.S. dollars, providing an enormous space requirement reduction compared to many competitive automatic baggers, and being of substantially less cost. Yet the bagging and collecting method and apparatus according to the invention are able to save significant amounts of money by minimizing the overage in bags of articles produced (while still ensuring that the articles weigh more than a predetermined amount). For example, the method and apparatus according to the invention are able to save about 1.5 oz. for a three pound bag of apples with fruit size between 4 to 6 oz., compared to the most effective prior art commercial equipment. Despite these advantages the apparatus according to the present invention is simple and compact, with no difficulty to construct or maintain components.
The basic apparatus according to the present invention that allows it to achieve the desirable results set forth above include a number of individual weighing devices, referred to as "weigh chutes" which are associated with a first conveyor for feeding articles to an essentially conventional primary weighing pan. Preferably the articles are singulated to the weigh chutes by the conveyor. Also, associated with the automatic bagger according to the invention is a shunt device for diverting fruit being conveyed by a second conveyor, which conveys the fruit or other articles in a second direction transverse to the direction of conveyance of the first conveyor. The shunt is controlled by a pair of fluid cylinders to provide either no flow, maximum flow, or an intermediate flow, of articles being conveyed by the second conveyor to the first conveyor.
According to one aspect of the present invention, a bagger for discrete articles, such as apples or other pieces of fruit, is provided. The bagger comprises the following elements: A primary weigh pan for weighing articles fed thereto, and upon the articles therein exceeding a predetermined weight, discharging the articles. First conveying means for delivering articles to the primary weigh pan, the first conveying means including a plurality of discharge structures, the discharge structures immediately adjacent the primary weigh pan. Each of the discharge structure comprising a weigh device (chute), and a releasable stop finger for releasably holding an article in the weigh device, each weigh device large enough to receive one of the articles therein. And, control means for: activating the fingers for holding articles in the weigh devices once the primary weigh pan senses a weight of articles just short of the predetermined weight; for receiving the individual weights of the articles in the weigh devices; for calculating the desired individual or combination of article weights in the weigh devices which is the lowest weight which will cause the articles in the primary weigh pan to exceed the predetermined weight; and for activating the fingers associated with the calculated desired individual or combination of weigh devices. The control means may include a computer controlled by software to perform the desired calculations and control functions.
The first conveying means preferably comprises a plurality of lanes, one associated with each of the weigh devices, for singulating articles to the weigh devices. The control means preferably includes a plurality of sensors (e.g. photosensors), one associated with each of the lanes for sensing passage of each article along each lane. The control means typically controls the first conveying means, in response to sensing by the sensors, so that the first conveying means is arrested and the stop fingers stop articles in the weigh devices when the primary weigh pan receives the number of articles expected to provide the predetermined weight minus X, where X is a positive integer less than or equal to the number of weigh devices. Typically four lanes are provided for the first conveyor, and four weigh devices, and X then preferably equals 2.
Second conveying means are also provided for feeding articles in mass to the first conveying means, and shunt means are associated with the second conveying means for controlling the feed of articles to the first conveying means from the second conveying means. The shunt means preferably comprises a bar disposed at approximately the level of the second conveying means, and first and second fluid cylinders operatively pivotally connected to the bar for controlling the position of the bar with respect to the second conveying means to either allow full feed, partial feed, or no feed of articles from the second conveying means to the first conveying means. For example the shunt means may include a crank arm rigidly connected to the bar with one of the fluid cylinders pivotally connected to the crank arm and the other pivotally connected to a stationary frame, with the fluid cylinders rigidly connected to each other. A first conveying means conveys articles in a first direction and the second conveying means conveys them in a second direction, substantially perpendicular to the first direction, the shunt means deflecting articles from the second direction to the first direction.
According to another aspect of the present invention, a method of automatically collecting at least a predetermined weight of discrete articles each having a weight significantly lower than the predetermined weight, using a plurality of individual weigh devices (chutes), and a primary collecting pan weighing device, is provided. The method comprises the steps of automatically: (a) Feeding a plurality of articles past the individual weigh devices until a number of articles having a collective weight just below the predetermined weight enter the collecting pan. (b) After step (a), stopping further feeding of articles past the individual weigh devices, so that an article is provided in each of the weigh devices. (c) Measuring the collective weight of articles in the collecting pan and comparing it to the predetermined weight to determine a shortfall weight. (d) Determining the weights of each of the individual articles in each of the individual weigh devices. (e) Calculating the desired individual or combination of individual articles from the weigh devices that is the closest to, yet exceeds, the shortfall weight. (f) Releasing only the individual article or articles from the individual weigh devices having articles which comply with the desired individual or combination of step (e), so that it or they enter the collecting pan. And, (g) discharging the articles with a collective weight approximately at, but exceeding, the predetermined weight from the collecting pan.
The method described above may be practiced in at least three different ways, in each case step (a) being practiced to count the number of articles fed to the collecting pan. Step (b) may be practiced to stop the feed of articles to the collecting pan once the number of articles fed to the pan is the same as the number of articles in the pan when step (g) was practiced for the most recent previous pan, minus X (the whole integer described above, e.g. for a four lane conveyor). Alternatively, step (b) may be practiced to stop the feed of articles to the collecting pan once the number of articles fed to the pan is the average of the number of articles in the pan when step (g) was practiced for the several most recent previous pans, minus X. In still another alternative, step (b) may be practiced to stop the feed of articles to the collecting pan when a number of articles times the average weight of articles minus X has passed into the pan, in which case the average weight of the articles is calculated. Normally the articles are pieces of fruit, and there is the further step of bagging the articles discharged in step (g) with conventional. bagging equipment, such as shown in U.S. Pat. Nos. 4,177,621 or 5,174,094, the disclosures of which are hereby incorporated by reference herein.
It is the primary object of the present invention to provide for the efficient and effective automatic collection and bagging of discrete articles so that there is a minimum amount of overage in each bag, and in a substantially continuous manner. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.